diff mbox

[v3,4/8] scrub: bugfix: mirror_num off by one

Message ID a841550267e24b620e00d472bb40bb661005f559.1310053204.git.list.btrfs@jan-o-sch.net (mailing list archive)
State New, archived
Headers show

Commit Message

Jan Schmidt July 7, 2011, 3:48 p.m. UTC 
Fix the mirror_num determination in scrub_stripe. The rest of the scrub code
did not use mirror_num for anything important and that error went unnoticed.
The nodatasum fixup patch of this set depends on a correct mirror_num.

Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
---
 fs/btrfs/scrub.c |   10 +++++-----
 1 files changed, 5 insertions(+), 5 deletions(-)

Comments

Jan Schmidt July 19, 2011, 3 p.m. UTC | #1 
On 07.07.2011 17:48, Jan Schmidt wrote:
> Fix the mirror_num determination in scrub_stripe. The rest of the scrub code
> did not use mirror_num for anything important and that error went unnoticed.
  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
This just turned out not to be the case. Please ignore this. I'll send a
corrected version, soon.

The bug introduced with this series does nothing harmful by itself, but
can prevent error correction.

-Jan
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diff mbox

Patch

diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index 221fd5c..15fed35 100644
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -930,21 +930,21 @@  static noinline_for_stack int scrub_stripe(struct scrub_dev *sdev,
 	if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
 		offset = map->stripe_len * num;
 		increment = map->stripe_len * map->num_stripes;
-		mirror_num = 0;
+		mirror_num = 1;
 	} else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
 		int factor = map->num_stripes / map->sub_stripes;
 		offset = map->stripe_len * (num / map->sub_stripes);
 		increment = map->stripe_len * factor;
-		mirror_num = num % map->sub_stripes;
+		mirror_num = num % map->sub_stripes + 1;
 	} else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
 		increment = map->stripe_len;
-		mirror_num = num % map->num_stripes;
+		mirror_num = num % map->num_stripes + 1;
 	} else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
 		increment = map->stripe_len;
-		mirror_num = num % map->num_stripes;
+		mirror_num = num % map->num_stripes + 1;
 	} else {
 		increment = map->stripe_len;
-		mirror_num = 0;
+		mirror_num = 1;
 	}
 
 	path = btrfs_alloc_path();